[Tommy]

If you can't lock the front brakes before the rear with full adjustment on the balance bar, you need a SMALLER diameter front master cylinder. More than likely one step smaller will do (e.g., from 3/4 to 11/16 or 5/8). Applying the same pedal pressure to a smaller diameter cylinder results in a higher fluid pressure (PSI) in the brake fluid going to the calipers. But the master cylinder has to be large enough to provide the volume of fluid needed by the caliper. That is why you want to step down only as much as needed. . . . BTW, if you do swap out master cylinders, be sure to follow the instructions about bench bleeding the MC BEFORE you install it. Skipping that step has caused problems for many DIY mechanics.